This invention relates to gunsmith's tools, and more particularly relates to a tool by which a gunsmith may more precisely and efficiently perform surface-finishing work upon the muzzle of a shotgun or similar firearm.
A substantial part of the average gunsmith's business activity is devoted to shortening the barrels of firearms brought to him by customers. In the case of firearms of the shotgun type, this is necessary when the customer desires to change the "choke" of his gun, either merely by reducing the barrel length or by the addition of a POLYCHOKE.RTM. or similar muzzle device to it. In both of the foregoing cases the gunsmith must first cut off a portion of the muzzle of the gun's barrel, which step is customarily performed by use of a lathe or the like, and then must hand-finish the cut end surface of the muzzle for the purpose of smoothing the same and of producing a "square" (i.e., perpendicular) relationship between it and the barrel's axis. The finishing may at times also include some further shortening of the barrel to bring it to precisely the desired reduced length. When the foregoing muzzle-finishing work is done by the use of a conventional metal-cutting file, as is now the customary practice, it is exceedingly laborious and time-consuming. It requires considerable alternate filing and gauging, and even then frequently fails to produce a precisely "square" muzzle surface.